1. Field of the Invention
The invention relates to changeable encoded information carrying characters, including bar-code like indicia. More particularly, the present invention relates to embodiments of machine readable, changeable or alterable indicia, wherein the change is related to one or more monitored parameters or variable quantities.
2. Background and Objects of the Invention
The advent of machine readable indicia has been long noted in the art. Such indicia, including for example bar code symbols and other specialized characters, enable encoded data to be read by suitable known apparatus to accurately determine the encoded data. It is this characteristic that has lead to the rapid acceptance of such coding arrangements as defacto standards, especially in inventory intensive establishments that must manage and track a large plurality of items with a significant accuracy. Presently there are a number of industry symbologies and accepted standards available in the art, and a full range of devices to accurately and rapidly read (scan) these indicia.
There is also an on-going need to provide assaying methods, manufactures, and apparatus that provide “assay result indications” which are not subject to errors due to human interpretation, transcription, and or translation. The assay may be required to monitor or determine the levels of parameters and variable quantities. For example, the monitoring of temperature, humidity, saline concentrations (of a fluid), gas concentrations (e.g., the level of exhaust fume gases), chemical residues and associated concentrations, light intensities, magnetic field strengths, radiation exposures, etc. It should also be noted that it is often advantageous to provide an assaying means with a ‘memory’ capability. For example, it may be desired to monitor if the maximum temperature a package reached in transit, has exceeded a critical level.
Objects of the present invention are, therefore, to provide new and improved assaying arrangements to monitor one or more parameters (or variables) having one or more of the following capabilities, features, advantages and/or characteristics:                an assaying system that produces machine readable result indications;        machine readable indicia having changeable or alterable encoded data content;        assay provided by “elements” composing a machine readable indicia;        a reliable and expeditious assaying arrangement;        provides assay means wherein changes and results detected and indicated may be provided as not “human readable”, and thus are not subject to interpretation and possible unauthorized dissemination;        may be employed on-site using a number of relatively low cost “off-the-shelf” components;        assaying means includes analysis elements that are arranged to provide an optically detectable machine readable change in the assaying indicia; and        inherently configurable to restrict an assay administrator, or other persons, access to the assay results.        
The above indicated advantages, characteristics, objects, and or associated novel features of the present invention, as well as others, will become better understood with a careful review of the description and figures provided herein. Attention is called to the fact, however, that the drawings are illustrative only. Variations are contemplated as being part of the invention, limited only by the scope of the appended claims.